1. Field of the Invention
The present invention relates to a developing device with sealing provided at a periphery of a developer supply opening.
2. Description of Related Art
A developing cartridge generally includes a frame having a toner storage portion for storing toner and a longitudinal toner supply opening from which the toner stored in the toner storage portion is supplied, a supply roller extending along the toner supply opening and rotatably supported on the frame within the toner storage portion, and a developing roller extending along the toner supply opening and rotatably supported on the frame outside the toner storage portion such that toner is supplied from the supply roller to the developing roller.
For the purpose of preventing toner leakage from the developing cartridge, the periphery of the toner supply opening is generally sealed by a sheet-like seal member. This seal member is fixed at its one end to the frame through a double-sided adhesive tape adhered along the one end of the seal member, and contacts at its other end with the outer periphery of the developing roller. Namely, the seal member is supported in a cantilevered fashion by the one end fixed to the frame, which serves as a fixed support, and bridges and seals between the frame and the outer periphery of the developing roller.
However, the seal member is always in contact by pressure with the developing roller, and deflection of the seal member resulting from this pressing force causes the double-sided adhesive tape to peel off from the frame. If the seal member partly peels off from the frame, toner leakage may occur.
In order to eliminate this disadvantage, it may be conceivable that the area of the double-sided adhesive tape is increased to prevent peeling of the tape. However, there is also a requirement to reduce the size of the developing cartridge, which makes it difficult to provide a large adhesion surface on the frame around the developing roller.
In view of the above, it would be desirable to provide a developing device comprising a seal member which is configured to suppress peeling of an adhesive member from the adhesion surface of the frame without increasing the area of the adhesion surface.